White bread as a diet staple can lead to obesity, according to a new study. The study was scheduled for presentation on Friday at the European Congress on Obesity in Bulgaria. It does not actually show, however, a cause-and-effect relationship between white bread consumption and weight gain, just an association.

When researchers tracked the eating habits and weight of more than nine thousand university graduates for an average of five years, it showed that participants who ate only white bread and had two or more portions of white bread a day were 40 percent more likely to become overweight or obese than those who ate less than one portion of white bread a week.

There was no significant link between eating whole grain bread only and becoming overweight or obese. This may have to do with the types of carbohydrates, fiber content and other ingredients in whole grain bread.